The speed profile evaluation method in the vehicle operation

Abstract

In this paper the authors present new approach to testing procedure for light vehicles which involves a better characteristics describing parameters. This method will allow one to obtain better correlation between the real output measurements and theoretical inputs used in the modelling. The new vehicle testing procedure, the Worldwide harmonized Light vehicle Test Procedure (WLTP) was introduced in 2017, whose purpose was to better emulate the vehicle natural operation, than the previously used test - the New European Driving Cycle (NEDC). It is our belief, that in the NEDC, the speed profile test might have been created for convenience of a study rather than a model for describing the real operations parameters. The differences in the outputs between the laboratory testing and real outputs convinced the experts to review the procedures and to implement some changes in the WLTP test procedures. These changes resulted in improved randomized speed profiles of various vehicles, which also attempt including driving habits of the drivers. However, there cannot be created universal profile for every case, therefore the differences between theoretical and the real one should be noticed. As a result, we were able to create a model and an instrument which can indicate the differences between the real conditions and theoretical ones. It is our goal that the correcting factors should take care of differences in the evaluation methods of different studies.